A linear motion guiding apparatus for linearly guiding an article to be guided while circulating rolling elements such as rollers or balls infinitely in the inside is one of important mechanical elements giving significant effects on the moving accuracy of semiconductor manufacturing apparatus, super precision fabrication machines, super precision measuring instruments, etc.
The linear motion guiding apparatus is an apparatus including a guide rail provided with a rail side rolling element raceway groove, and a slider main body in which a slider side rolling element raceway groove opposed to the rail side rolling element raceway groove is provided and supported on the guide rail so as to be moveable axially by way of rolling of a plurality polarity of rolling elements arranged in the rolling element rolling channel formed between the slider side rolling element raceway groove and the rail side rolling element raceway groove. Then, the apparatus includes a rolling element return channel formed in the slider main body so as to be substantially in parallel with the rolling element rolling channel, an end cap attached to both ends in the moving direction of the slider main body to form an outer circumferential circulation groove for a semi-arcuate rolling element circulation channel for communicating the end of the rolling element return channel and the end of the rolling element rolling channel, and a return guide interposed between the end cap and the slider main body to form an inner circumferential circulation groove for the rolling element circulation channel at a position opposed to the outer circumferential circulation groove.
In a case where rolling elements of the linear motion guiding apparatus circulate the rolling element rolling channel, the rolling element circulation channel, and the rolling element return channel infinitely, periodical fine vibrations (hereinafter referred to as rolling element passing vibrations) are generated to greatly effectuate the moving accuracy of the equipments described above. The rolling element passing vibrations are developed when the rolling elements rolling in the rolling element rolling channel (load region) while undergoing load by pre-load or external load are released from the load upon exiting from the load region to the rolling element circulation channel (non-load region) or applied with additional load upon entrance from the non-load region to the load region.
Suppression for the rolling element passing vibrations is conducted by applying a crowing fabrication to both ends of the slider side rolling element raceway groove forming the rolling element rolling channel thereby gradually conducting change of load upon exit and entrance of the rolling element to and from the load region (for example, in Patent Document 1).
Patent Document 1: JP04-54310A (FIG. 11, FIG. 15).
However, the linear motion guiding apparatus described above involves a problem that the operability and the noise level are tended to be worsened in a case where a large load exerts on the slider main body or a large installation error is caused by caulking.
The present invention has been accomplished in view of the foregoing situations and it intends to provide a linear motion guiding apparatus capable of attaining the improvement in the noise characteristics by the reduction of the traveling sounds and attaining the smooth operability for the slider main body, as well as capable of improving the moving accuracy by the reduction of the rolling element passing vibrations.